Propeller structure



H. J. BAKER.

PROPELLER STRUCTURE.

APPLICATION FILED MAY 14. I92].

1,435,791 Patented Nov. 14, 1922.

SHED I.

2 SHEETS- H. J. BAKER.

PROPELLER STRUCTURE.

APPLICATION FILED MAY 14, I921.

Patented Nov. 14, 1922.

2 SHEETS-SHEET 2.

INVENTOR A'I'I'ORNEY Patented Nov. 14, 1922.

HAROLD J. BAKER, 9F NORTH STREET, MICHIGAN.

PROPELLER STRUCTURE.

Application filed May 14, 1921.

To all whom it may concern:

Be it known that I, HAROLD J. BAKER, a citizen of the United States, residing at North Street, in the county of St. Clair and State of Michigan, have invented new and useful Improvements in Propeller Structures, of which the following is a speclfication.

This invention relates to a propeller structure and has for its primary object a construction that is lighter, more durable and occupies less space than the usual propellers now in use.

An object of the invention is to provide a collapsible propeller so as to occupy a minimum amount of space when not in use.

Another object of the invention is the provision of a propeller that will not be affected when rotated below a certain number of revolutions a minute.

With these and other objects in view the invention will be better understood from the following detailed description taken in connection with the accompanying drawing wherein:

Fig. 1 is a plan View of the propeller in collapsed position.

Fig. 2 is a plan view in operative position.

The remaining views are sectional views.

Again referring to the drawing illustrating one of the many constructions of my invention the numeral 1 designates a base in the form of a disc keyed to the drive shaft 2. This disc has pivoted thereto as indicated at 3'any number of blades shown in this particular case two in number and designated by the numerals 4 and 5. These blades are given a circular curve formation so that when forced to an operative position as hereinafter described the same will have the proper action upon the air to propel the airplane. It will be noted that when the blade is in collapsed position the edge 6 thereof conforms to a circular edge 7 of the disc thereby accomplishing a more compact arrangement and besides, prevent the action of the blades upon the atmosphere when the engine is running at a relatively low speed.

Extensions 8 and 9 of the blade are connected together by a coil spring 10. A very important feature of my invention is that the resiliency of the spring 10 is the proper degree to hold the blades in a collapsed po sition when the motor is running at a relatively low speed thereby enabling motors to be worked upon while running without Serial No. 469,655.

the tendency of the propeller to move the airplane.

The guiding means 11 is provided for guiding the position of the blades and to 69 accomplish a more substantial driving ac tion, and in this particular case the guiding means consists of a guide 12 secured to the disc and working in the slots 18 and l i in the blade. The novel manner of shaping and 5 arranging the blades enables the same to move in a position directly behind the disc 1 thereby preventing the free flow of air to the blades thereby destroying the propelling action thereof. In other words the disc 1 forms a shield against the inrush of air currents to take the place of the air displaced by the rotation of the propeller blade.

From the foregoing description taken in connection with the accompanying drawing it will be seen that I provide a propeller structure of a very simple substantial formation and which occupies very little space when not operating which has a number of so obvious advantages.

It is, of course, to be understood that the invention may be constructed in various other manners and the parts associated in diflerent relations and, therefore, I do not desire to be limited in any manner except as set forth in the claims hereunto appended.

Having thus described my invention what I claim is:

1. A propeller structure comprising a base for connection to a drive shaft, and blades pivoted to the base to swing to an operative position upon the base reaching the pro-determined number of revolutions.

2. A propeller structure comprising base for connection to a drive shaft, and blades pivoted to the base to swing to an operative position upon the base reaching the pre-determined number of revolutions, and means for holding the blades in an operative position until the base reaches said number of revolutions.

3. A propeller structure comprising a disc for connection to a drive shaft and curved blades pivoted to the disc to move to an operative position by centrical action.

4. A propeller structure comprising a disc for connection to a drive shaft and curved blades pivoted to the disc to move to an operative position by centrical action, and a spring coil arranged to normally hold the blades in an inoperative position.

A propeller structure comprising a disc for connection to 2: drive shaft, and. blades pivoted to the disc and when in an inoperative position conforming to the shape of the 5 disc, and adapted to swing to an operative position When the rotation of the disc reaches a pre-determined speed.

6. A propeller structure comprising a,

disc for connection to a drive shaft, and 10 blades pivoted to the disc and when in an inoperative position conforming to the shape of the disc, and adapted to swing to an operative position when the rotation of the disc reaches a pre-determined speed, and a coil spring connected to the blades for holding 15 the same "in an inoperative position until the disc reaches the required speed, a guide connection between each blade of the disc.

In testimony whereof I afiix my signature.

HAROLD J. BAKER. 

